One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(9,10,14,15)(11,12,17,20)(13,16,21,22)(18,19,23,24)(25,26,31,32)(27,33,28,30)(29,37,39,34)(35,40,36,38)(1,3,5,8)(2,6,4,7)(25,27,31,28)(26,30,32,33)(29,35,39,36)(34,40,37,38)(1,2,5,4)(3,6,8,7)(10,15)(11,17)(16,22)(18,23)(26,32)(27,28)(34,37)(35,36)(1,2,5,4)(3,6,8,7)(9,11)(10,12)(13,18)(14,17)(15,20)(16,19)(21,23)(22,24)(25,28,31,27)(26,33,32,30)(29,36,39,35)(34,38,37,40)(9,12)(10,11)(13,19)(14,20)(15,17)(16,18)(21,24)(22,23)(25,29,31,39)(26,34,32,37)(27,35,28,36)(30,40,33,38)(1,4,5,2)(3,7,8,6)(9,13,14,21)(10,16,15,22)(11,18,17,23)(12,19,20,24)(25,30,31,33)(26,27,32,28)(29,38,39,40)(34,36,37,35)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.